Richard Whittam QC, prosecuting, questions Thomas Mair in a court artist's drawing during the murder trial at the Old Bailey. Picture: SWNS

Tom Little, prosecuting, said: “We have heard expert evidence about this, that the barrel and stock had been cut down.

“I think you found numerous blood stains on the rifle?”

She replied: “I did, yes.”

The DNA profile from the gun had a “one-in-a-billion” match to Mair, the court heard.

DNA from the blood found on the gun also had a one-in-a-billion match to Mrs Cox, Ms Parkinson confirmed.

Ms Parkinson said: “The blood was airborne, but because there were only a few spots around that location, we couldn’t determine exactly how they were deposited.

Murder accused Thomas Mair. Court sketch: SWNS

“For example, if somebody is shot, then blood can be projected back onto the weapon.”

However if the weapon was near someone exhaling blood through their airwaves, or had blood in their mouth, “that could also project spots on to the weapon”, she told the court.

But she added: “What I can say is that the source would be close to the weapon.”

A bloody handprint was also found on the back of Mair’s brown jacket recovered nearby in Union Street, which matched Mrs Cox’s DNA, jurors were told.

Ms Parkinson said: “It would suggest she had made contact with the jacket at a time when her hand was wet with blood.”

None of Mr Kenny’s DNA was found on the knife, the court heard.

Prosecutor Tom Little asked the witness: “Does that suggest, in your view, that the knife was used to stab Helen Joanne Cox again after it had been used to stab Bernard Carter Kenny?”

She replied: “It does, yes. There was no evidence of blood. I would have expected some.

“It would suggest that the knife had been used on Helen Joanne Cox again.”

Ms Parkinson examined the outside of the library on the day Mrs Cox was killed, along with the body.

Her tights were “extensively laddered” and there were holes in the knees.

Mr Little said: “Did you form the view that Helen Joanne Cox had been crawling or struggling along the ground, resulting in that damage to her tights?”

She confirmed that she did, adding that “she had not been up very long while she was bleeding”.

Photos were shown to the court of bloody fingermarks on the nearby car which had matched Mrs Cox’s DNA.

Mr Little asked: “Was there also heavy blood staining which had pooled along the bottom edge of the rear of the vehicle?”

She said: “There was, yes.”

It suggested Mrs Cox had touched the car after sustaining “at least one injury, such that her hands were heavily stained in blood”, the court was told.

Mair was armed with British-made hollow-point rifle bullets more commonly used to kill vermin in a “humane” way, the trial heard.

A plastic bag found in a holdall when the alleged killer was arrested was found to contain 25 live .22 calibre rounds, jurors were told. Twelve of the rounds were lead hollow-point cartridges made by British maker Eley, firearms expert Andre Horne told the trial. The other 13 were made by a German firm.

Mair shouted out “Britain first” and “keep Britain independent” as he attacked the pro-EU MP, and later told police he was a “political activist”, the Old Bailey heard.

In the days leading up to the attack he accessed extreme far-right material, including some about the Nazis, and white supremacists, on library computers, it is claimed.

Mair, of Birstall, West Yorkshire, denies murder, grievous bodily harm with intent, possession of a firearm with intent to commit an indictable offence and possession of an offensive weapon - namely a dagger.

The trial continues.

The family of Jo Cox, Jean Leadbetter (mother), Kim Leadbetter (Sister) and Gordon Leadbetter (Father) arrive at the Old Bailey. Picture: SWNS